Instrument for navigation and like purposes



E. ZONA.

INSTRUMENT FOR NAVIGATION AND LIKE PURPOSES.

APPLICAIION FILED APR. I8, 1918.

1,305,047., Patnted May 27,1919.

- 7 INVENTOR Ez/o ZONA,

To all whom it may concern:

and use E ra EZIO zone, oremaoa, m

mssmumn'r iron NAVIGATIOH' Ii LIKE ruosrs.

Be it known that I, Ez1o ZQNA, a subject of the King of Italy, residing at Genoa, 1n the dom of Italy, have invented new Improvements in or Relating to Instruments for Navigation and like Purposes.

The present invention refers to an instrument which permits of resolving'in a quick and easy manner all those problems of plane navigation, the solution of which depends "'from' the determination of the elements of a lane triangle.

he solutlon of these problems is obtained with the aid' of a plane chart to which the instrument is applied, avoiding thus tracing on the same any construction lines which stain the paper and the canceling of them, a practice which, even if the llnes are very lightly traced, may give rise to serious inconveniences. p

There exists already instruments for the solution of problems relating to navigation,

and which comprise a disk, a ring concentric therewith and. a square provided with linear and angular graduations, but none of said'instruments possess a transparent baseand they are not intended for use in combination with a nautical chart on whlch the lines traced on the disk and on the square appear by the efl'ect'of its transparency as if they were traced on the chart ltself.

In the annexed drawing is shown a plan .view of the instrument, which consists of a -transparent and stifl' circular dlsk -zprovided onits edge --swith a graduation from 0 to 360.

A ring Z- concentric with the disk zis connected to the same by means of small'clamps fixed on the latter,'which permit the ring Z to turn freely. This ring is also provided with a graduation from 0 to 360?. On the surface of the disk a is traced a scale comprising 30 equal divisions. On the center 0 of the circle are pivoted four alidades a, b cand d each of which has one of its edges passing through the common center o of the disk and the ring. Starting from the center, these alidades are graduated and each division of their graduation corresponds to a division of the disk. The

instrument is further provided with set screws z'- which serve to. clamp the alidades in any desired position and w th a small hole in the center oto recelve a specification q L mm Patented May 2'3, rare. Application filed a niis, isle. sermm. 229,423.

piplessing point to indicate the position of the s p ample a few problems which can be solved by the use of the above described device. Problem I .To mark on the chart the position of the ship the longitude are given; v v

The two alidades a, and -b-'-, are

minutes of the given latitude, and the cen-" ter 0 will give the position of the ship. This is evident, because the two alidades which are at right angles to each other remain also at right angles to the two scales of latitude and longitude. i

Problem II.T0 determine the latitude and longitude of a given point on the plane chart. I

Clamp two alidades at right angles as in Problem I, set-the instrument on the chart ,with one of the diameters 0-180, and 9027 0 successively on a parallel-or meridian in such a way that the alidade at right angles to said diameter passes through the point of the ship. In the first case the alidade will give the meridian of the point and consequently will indicate on the re spective scale the longitude and in the second case the latitude.

Problem; l[I.To trace the ship from a given starting point.

'fter having set the instrument as in the previous cases, the third or fourth alidade, which is free, is rotated until it indicates the course to be followed. The degrees as read .on the edge of the ring '-awill indicate the real course. If a magnetic or deviated course is desired, it will suflice to rotate the circle 2-' in such a way that its zero differs from that of the ring a by 'an angle equal in value and sign to the magnetic dec-. lination or to the total error. Evidently the courses read on the ring will be respectively magnetic or deviated.

Problem IV.'To mark the point of the ship, two bearings being'known.

course of a Hereinafter are mentioned by way of exwhen the latitude and set at right angles to each other, which can easily be done ,Clamp two or three alidades on theangles corresponding to'the given bearing by reading the angles on the graduation of theouter ring and place the instrument in such a position that one of the diameters 1 80, or 9O27 0 passes respectively through a me-' ridian or a parallel.

The instrument is then successively dis- -placed in such. a way that the three alldades requested.

marking the angles of the bearings pass su'c- Problem V.Having the coordinates of a point, to obtain the bearings of land points. The instrument is placed as in Problem II and the free alidades are made to pass through the oints of which the bearings are he degrees marked by the edges of the alidades give the value of the bearings- The instrument can also be used as stav tion pointer.

One of the alidades is clamped on 0 of I the outer circle and the other two, one on the right and one on the left of the first one,

so as to form with same the two angles measured with thesextant or with the circle.

After havingthus adjusted the alidades, the instrument can be used as a common station pointer. In fact if one of the alidades is clamped on 0, the other two alidades can be clamped on the right and on the left under an angle which is equal to the measured one.

Having determined the point,without moving the instrument, the two alidades are disengaged and set one on 0 and the other on 180 of the outer graduation and the second one on 90 or on 270. The whole'system formed by the outer ring and the three alidades is then rotated until the two 0180 pass through the same number of degrees and minutes of the longitude, giving thus the longitude, while the third alidade gives the latitude. The fourth alidade w ill indicate the course to be followed.

Briefly the scale and the scales of the a1i-' dades serve to solve any problems of plane navigation the solution of which depends upon the solution of a plane triangle. In

fact taking as base of the triangle to be solved, the line of the scale corresponding to thediameter 0180 of the inner disk and disposing conveniently one or two alidades, all the triangles necessary for the resolution of the problems can be constructed.

The following advantages are obtained by the use of this new device: rapidity and accuracy in the solution of all problems, complete exclusion of parallels, the tracing of which proves to 'be always tiresome even if by means of rollers on account of the ineyitable displacements especially if the table is not perfectly even, and lastly the possibility of reading at the same time the course and the real and deviated or magnetic bearings.

This device also eliminates the use of any pencil which stains the paper and requires continuous canceling causing thus often dcteriorations of the paper and even the disappearance of marks for little but dangerous obstructions and soundings which may cause sometimes very grave consequences.

Claim A navigationinstrument comprising a Q transparent disk provided with a circular scale and having two series of straight parallel lines inscribed thereon, the lines of each series being arranged at right angles to the lines of the other and being numbered from the center of said disk, an annulus having a circular scale rotatably connected to f and concentric with said disk, and four alidades extending across said disk and annulus and pivoted for independent rotation at the center of said disk, each alidade having a graduated straight edge radiating from said center. 1

In testimony whereof-I have signed my name to this specification in the presence of two subscribing witnesses.

' I EZIO ZONA. Witnesses: v

WILLIAM P. SHOCKLEY,

EDWIN N. ATHERTON. 

